Corrected version:

The modern world is growing at a faster rate in every sphere of life, but the major hindrance is various health ailments, with obesity being the major contributor to many diseases.

Explanation: 

Replaced "circle of life" with "sphere of life" for clarity. Removed the repetition of "causes" and rephrased the sentence for better flow.

Improved version:

The rapid growth of the modern world in all aspects of life is hindered by various health ailments, with obesity being a significant factor in the development of numerous diseases.

Corrected version:

Currently, there are more overweight people than ever before.

Explanation: 

Added the word "currently" for better sentence structure and clarity.

Improved version:

Presently, the number of overweight individuals has reached unprecedented levels.

Corrected version:

There are numerous reasons that cause obesity and can have adverse effects on the body, leading to serious health issues.

Explanation: 

Changed "causes" to "cause" to match the subject-verb agreement. Replaced "affects" with "effects" for correct usage. Added the article "the" before "body" for clarity.

Improved version:

There are multiple factors that contribute to obesity and can have detrimental effects on the body, resulting in severe health complications.

Corrected version:

Obesity is a major concern for a substantial number of people. 

Explanation: 

Replaced "concerning" with "concern" for better sentence structure and clarity.

Improved version:

Obesity is a significant concern for a considerable portion of the population.

Corrected version:

One of the main causes behind this is the advancement in technology.

Explanation: 

Added the article "the" before "advancement" for correct usage.

Improved version:

One of the primary factors responsible for this is the advancement of technology.

Corrected version:

With the development of technology, people rely more on electronic gadgets for most of their work.

Explanation: 

Replaced "in" with "of" for correct usage. Rearranged the sentence for better flow.

Improved version:

With the progress of technology, individuals increasingly depend on electronic devices for their daily tasks.

Corrected version:

Many people are engaged in using social media, playing games online, and even doing their work on gadgets like mobile phones and laptops. 

Explanation: 

Removed the word "great" as it is unnecessary. Added commas to separate the different activities for better clarity.

Improved version:

A significant number of individuals are immersed in activities such as social media usage, online gaming, and even work tasks on devices such as mobile phones and laptops. 

Corrected version:

Due to a lack of physical activity and excessive reliance on technology, it leads to weight gain and makes people obese.

Explanation: 

Added the article "a" before "lack" for correct usage. Added the word "excessive" before "reliance" for better description. Removed the comma and replaced "and" with "it" for better sentence structure.

Improved version:

The combination of insufficient physical activity and excessive dependence on technology results in weight gain and obesity.

Corrected version:

An unhealthy lifestyle is a second major contributor to obesity.

Explanation:

Added the article "an" before "unhealthy" for correct usage. 

Improved version:

An unhealthy lifestyle is another significant factor contributing to the prevalence of obesity.

Corrected version:

Nowadays, people tend to eat junk food and processed and packaged foods.

Explanation:

Added the conjunction "and" to separate the two types of food for clarity.

Improved version:

In the present era, individuals have a tendency to consume unhealthy junk food and processed and packaged meals.

Corrected version:

As life is becoming faster, people do not have enough time to cook food, and these processed and packaged foods are readily available, making it easier for them to eat.

Explanation:

Removed the article "the" before "life" for correct usage. Added a comma before "and" to separate the two clauses. Removed the repetition of "easily" for better sentence structure.

Improved version:

With the increasing pace of life, individuals face time constraints that limit their ability to cook meals, leading to a reliance on easily accessible processed and packaged foods.

Corrected version:

However, this regular eating of junk food can have serious effects on the body.

Explanation:

Added the article "the" before "body" for correct usage. 

Improved version:

Nevertheless, the regular consumption of junk food can have detrimental effects on one's physical well-being.

Corrected version:

Serious ailments like heart attack, high blood pressure, diabetes, etc., can be caused by obesity.

Explanation:

Added a comma before "etc." for correct punctuation. 

Improved version:

Obesity can contribute to the development of severe conditions such as heart attacks, high blood pressure, diabetes, and more.

Corrected version:

Being overweight can affect the social and physiological lifestyle of people, making it difficult for them to survive.

Explanation:

Added the article "the" before "social" for correct usage. 

Improved version:

Excessive weight can significantly impact individuals' social and physiological well-being, posing challenges to their overall quality of life.

Corrected version:

In severe cases, obesity can also lead to cancer, which is an incurable disease.

Explanation: 

Replaced "uncurable" with "incurable" for correct spelling.

Improved version:

In extreme instances, obesity can even result in the development of incurable diseases like cancer.